In an internal combustion engine, especially on OHC (overhead cam shaft) engine, there is a problem of oil leakage from the fitted portions of the cylinder head cover within which the quantity of splashed oil becomes substantial due to the high speed and efficiency of the engine. There is also a problem of transmission of noise as caused by the valve actuating system.
The present invention provides a structure for securing a cylinder head cover to the cylinder head, which structure effectively overcomes the above problems. More specifically, the structure of this invention is able to provide a desirable seal between the cover and the mounting bolt to effectively prevent leakage of oil from the cover, while at the same time permitting the use of a seal formed from an elastomeric material which not only forms an effective sealed relationship, but also minimizes the transmission of noise from the valve mechanism. The elastomeric seal is covered by a washer which protects the seal from the tightening cap, which washer is prevented from rotating by fitting over at least two bolts to thereby stationarily position and fixedly hold the washer. The seal also passes through a hole in the washer to sealingly contact a bottom wall on the cap to create a sealed relationship therewith.